Local energy decomposition analysis of hydrogen-bonded dimers within a domain-based pair natural orbital coupled cluster study

• Ahmet Altun,
• Frank Neese and
• Giovanni Bistoni

Beilstein J. Org. Chem. 2018, 14, 919–929, doi:10.3762/bjoc.14.79

• ]. They are typically carried out at the Hartree–Fock (HF) or density functional theory (DFT) level. In these schemes, the interacting system is treated as a supermolecule and the overall interaction energy is decomposed into various terms such as electrostatic interaction, charge transfer, polarization

• ][34][35][36][37][38][39][40][41]. Although these dimers have been studied extensively, the principal mechanisms of interaction between their constituting monomers are still under debate. The debate concerns the magnitude of individual terms and the importance of London dispersion, charge transfer and

• three contributions: the electronic preparation energy , the charge transfer or charge polarization contribution (), and London dispersion (). The relevant pair excitation contributions constituting these terms are shown pictorially in Figure 2. It may be useful to combine several terms depending on the

Two novel blue phosphorescent host materials containing phenothiazine-5,5-dioxide structure derivatives

• Feng-Ming Xie,
• Qingdong Ou,
• Qiang Zhang,
• Jiang-Kun Zhang,
• Guo-Liang Dai,
• Xin Zhao and
• Huai-Xin Wei

Beilstein J. Org. Chem. 2018, 14, 869–874, doi:10.3762/bjoc.14.73

• and characterizations are given in Supporting Information File 1. In order to further understand the structural properties of the materials and the possibility of charge transfer from donor to acceptor on electronic excitation, the electronic structure of the materials were analyzed by density

D–A–D-type orange-light emitting thermally activated delayed fluorescence (TADF) materials based on a fluorenone unit: simulation, photoluminescence and electroluminescence studies

• Lin Gan,
• Xianglong Li,
• Xinyi Cai,
• Kunkun Liu,
• Wei Li and
• Shi-Jian Su

Beilstein J. Org. Chem. 2018, 14, 672–681, doi:10.3762/bjoc.14.55

• donors (D) and electron acceptors (A) are introduced into the molecule to form an intramolecular charge transfer (ICT) state with a large twisting angle between the donor and the acceptor to achieve the separation of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO

• around 345 and 456 nm. The peaks at around 456 nm result from their ICT states from the donor to the acceptor, while the absorption below 380 nm is caused by their short π-conjugation. It is obvious that 2 has not only a higher oscillator strength (f) than 1 from its transition of charge-transfer states

• , but also a weaker oscillator strength from its local excited (LE) states. It could be considered that 2 has a better configuration, which is advantageous to intramolecular charge transfer compared with 1, which coincides with the conclusion from DFT calculation. The PL spectra of the materials in

Recent advances on organic blue thermally activated delayed fluorescence (TADF) emitters for organic light-emitting diodes (OLEDs)

• Thanh-Tuân Bui,
• Fabrice Goubard,
• Malika Ibrahim-Ouali,
• Didier Gigmes and
• Frédéric Dumur

Beilstein J. Org. Chem. 2018, 14, 282–308, doi:10.3762/bjoc.14.18

• spin–orbit vibronic coupling, in addition to the small ΔEST. Indeed, a small ΔEST is not sufficient to ensure for a TADF material an efficient RISC which is a vibronically coupled, spin–orbit coupling process with the involvement of the charge transfer state. To remain efficient, the spin–orbit

• generated, resulting in a greater intramolecular charge transfer and an increase of the oscillator strength. As a result, EQE of corresponding OLEDs increased from 13.5% (459 nm, (0.13, 0.09)) for B9-based devices to 20.2% (467 nm, (0.12, 0.13)) for B10-based devices. If the electron-to-photon conversions

• , respectively, determined for D1–D3. Changes in ΔEST were explained as follow: By introducing tert-butyl groups on the diphenylamine unit, the electron donating ability in D2 was reinforced compared to D1, red-shifting the charge transfer (CT) band and lowering the CT energy as well as ΔEST. By replacing the

Fluorescent nucleobase analogues for base–base FRET in nucleic acids: synthesis, photophysics and applications

• Mattias Bood,
• Sangamesh Sarangamath,
• Moa S. Wranne,
• Morten Grøtli and
• L. Marcus Wilhelmsson

Beilstein J. Org. Chem. 2018, 14, 114–129, doi:10.3762/bjoc.14.7

• using tCO and tCnitro [14]. Nitro groups introduce an increased charge-transfer character to chromophores, which generally results in absorption at lower energies [38][45]. Hence, tCnitro was envisioned to be able to accept the energy transferred from tC or tCO, and, thus serve as a FRET acceptor. The

Metal-mediated base pairs in parallel-stranded DNA

• Jens Müller

Beilstein J. Org. Chem. 2017, 13, 2671–2681, doi:10.3762/bjoc.13.265

• composed of metal-mediated base pairs only [10]. Possible applications of nucleic acids with metal-mediated base pairs exist in numerous fields [11]. More recently investigated areas include charge transfer in metal-modified DNA [12][13][14], the recognition of specific nucleic acid sequences [15][16][17

Structure–property relationships and third-order nonlinearities in diketopyrrolopyrrole based D–π–A–π–D molecules

• Jan Podlesný,
• Lenka Dokládalová,
• Oldřich Pytela,
• Adam Urbanec,
• Milan Klikar,
• Numan Almonasy,
• Tomáš Mikysek,
• Jaroslav Jedryka,
• Iwan V. Kityk and
• Filip Bureš

Beilstein J. Org. Chem. 2017, 13, 2374–2384, doi:10.3762/bjoc.13.235

• eventually intramolecular charge-transfer (ICT) [9][10] from the peripheral donors to the central DPP acceptor. Due to their generally D–π–A–π–D character and thus resulting centrosymmetric arrangement, the DPP derivatives were most frequently studied as third-order optical NLOphores, in particular as two

• longest-wavelength absorption/emission maxima (λmaxA/F), terminal absorptions (λend), Stokes shifts, and quantum yields of fluorescence (qF). The absorption spectra consist of two intense low-energy charge-transfer bands located within the range of 550–650 nm accompanied by weak high-energy bands found

One-pot syntheses of blue-luminescent 4-aryl-1H-benzo[f]isoindole-1,3(2H)-diones by T3P^® activation of 3-arylpropiolic acids

• Melanie Denißen,
• Alexander Kraus,
• Guido J. Reiss and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2017, 13, 2340–2351, doi:10.3762/bjoc.13.231

• vibrationally relaxed excited state. This is even more the case in the nearly perfect linear correlation of the Stokes shift with σR (r2 = 0.989) and can be interpreted as a significant structural change upon photonic excitation and excited state relaxation resulting from a considerable charge transfer

• spectroscopy revealed that the Stokes shifts are excellently correlated with Hammett–Taft's σR parameters indicating an extended degree of resonance stabilization as a result of a charge transfer character in the vibrationally relaxed S1-state. The fluorescence can be redshifted by employing 1,2

Dialkyl dicyanofumarates and dicyanomaleates as versatile building blocks for synthetic organic chemistry and mechanistic studies

• Grzegorz Mlostoń and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2017, 13, 2235–2251, doi:10.3762/bjoc.13.221

• six-membered heterocycles are discussed. Applications of dialkyl dicyanofumarates as oxidizing agents in the syntheses of disulfides and diselenides are described. The reactions with metallocenes leading to charge-transfer complexes with magnetic properties are also presented. Keywords: cycloaddition

• with diethyl phosphite in boiling 1,2-dichloroethane leading to the dialkyl dicyanosuccinates 96 [7]. Charge-transfer (CT) complexes Dialkyl dicyanofumarates E-1, similar to tetracyanoethylene (TCNE), are well-known as one-electron acceptors. They react with metallocenes 99, such as manganocenes [73

• ][74] and chromocenes [75], to form one-to-one charge-transfer salts 100 (Scheme 31), which are molecular magnets. Their physical properties depend on the size of the alkyl groups of the ester function [73]. Some chromocene complexes with E-1a,b were studied by means of X-ray crystallography [74][76

Complexation of molecular clips containing fragments of diphenylglycoluril and benzocrown ethers with paraquat and its derivatives

• Leonid S. Kikot',
• Catherine Yu. Kulygina,
• Alexander Yu. Lyapunov,
• Svetlana V. Shishkina,
• Roman I. Zubatyuk,
• Tatiana Yu. Bogaschenko and
• Tatiana I. Kirichenko

Beilstein J. Org. Chem. 2017, 13, 2056–2067, doi:10.3762/bjoc.13.203

• charge-transfer complex formed by the π-donor aromatic fragments of clips 1–5 and the π-acceptor dipyridinium fragment of paraquat derivatives 7–10 located in the pseudo cavity of the clip [20]. The intensity of this band increases with the raise of the molar ratio of paraquat:clip. The observed spectral

New electroactive asymmetrical chalcones and therefrom derived 2-amino- / 2-(1H-pyrrol-1-yl)pyrimidines, containing an N-[ω-(4-methoxyphenoxy)alkyl]carbazole fragment: synthesis, optical and electrochemical properties

• Daria G. Selivanova,
• Alexei A. Gorbunov,
• Olga A. Mayorova,
• Alexander N. Vasyanin,
• Igor V. Lunegov,
• Elena V. Shklyaeva and
• Georgii G. Abashev

Beilstein J. Org. Chem. 2017, 13, 1583–1595, doi:10.3762/bjoc.13.158

• causes the formation of excimers, which degrades the quality of the blue luminescence. On the other hand, the interaction of bulky side chains with each other can intensify an undesirable charge transfer in thin polymer films that can be overcome by introducing of terminal aromatic moieties into the

• example, compounds 7a,b demonstrate a yellow fluorescence in dichloromethane, DMF, acetone, and an orange one in ethanol, that is most likely connected with the enhancement of the intramolecular charge transfer under UV irradiation. The prepared compounds differ from each other only by the nature of the

• shown that incorporation of a thiophene unit into the structure of compounds 5a,b enforces the intramolecular charge transfer, which, in its turn, causes the decrease in the difference between the energy of the ground and excited states and the appearance of additional absorption bands in the 350–400 nm

Chemical systems, chemical contiguity and the emergence of life

• Terrence P. Kee and
• Pierre-Alain Monnard

Beilstein J. Org. Chem. 2017, 13, 1551–1563, doi:10.3762/bjoc.13.155

• ferricyanide, and EDTA used as an external sacrificial reductant was key to the reduction of the ferricyanide to ferrocyanide. Thus, simple compartments can harbor a directional charge transfer, induced by light harvesting. By contrast, even though the formation of proton gradients upon the irradiation of

Mechanochemical borylation of aryldiazonium salts; merging light and ball milling

• José G. Hernández

Beilstein J. Org. Chem. 2017, 13, 1463–1469, doi:10.3762/bjoc.13.144

• –solvent charge-transfer complex formation. Keywords: aryldiazonium salts; borylation; eosin Y; mechanochemistry; photocatalysis; Introduction The use of mechanical force to process materials or to induce chemical transformations is perhaps as old as the history of mankind itself [1]. Similarly, from

• light on the role of the photocatalyst in the borylation of the aryldiazonium salts. Under non-catalyzed LAG/irradiation conditions, charge-transfer complexes between 1a and appropriate organic solvents could be responsible for the fast generation of the aryl cations in the ball mill, leading to the

Molecular-level architectural design using benzothiadiazole-based polymers for photovoltaic applications

• Vinila N. Viswanathan,
• Arun D. Rao,
• Upendra K. Pandey,
• Arul Varman Kesavan and
• Praveen C. Ramamurthy

Beilstein J. Org. Chem. 2017, 13, 863–873, doi:10.3762/bjoc.13.87

• studied by UV–vis spectroscopy. The absorption spectra were obtained in chlorobenzene solution (Figure 4). All polymers showed a broad absorption in the lower energy region (450–650 nm) due to the intramolecular charge transfer (ICT) through the backbone of polymers and another broad peak in the higher

• indication of an efficient charge transfer between the donor and acceptor when excited at the wavelength of the absorption maximum of the donor. An efficient charge transfer between donor and acceptor is essential for good solar cell devices. The PL spectra of the polymers, consisting of PC70BM with various

N-Propargylamines: versatile building blocks in the construction of thiazole cores

• S. Arshadi,
• E. Vessally,
• L. Edjlali,
• R. Hosseinzadeh-Khanmiri and
• E. Ghorbani-Kalhor

Beilstein J. Org. Chem. 2017, 13, 625–638, doi:10.3762/bjoc.13.61

• mixture of 4H-1,3-thiazines 56 and 4,5-dihydrothiazoles 57. The mechanistic course of this reaction sequence is shown in Scheme 17 and involves the initial formation of the charge-transfer complex A between the iodonium ion and the triple bond. The 5-exo-dig cyclization of this intermediate gives rise to

• 4,5-dihydrothiazoles and the competing 6-endo-dig ring-closing process affords 4H-1,3-thiazines after conversion of the charge-transfer complex into the ring-opened iodovinyl B or bridged iodirenium C ions; (2) bromine-mediated cyclizations of both electron-poor and electron-rich N-propargylthioureas

Derivatives of the triaminoguanidinium ion, 5. Acylation of triaminoguanidines leading to symmetrical tris(acylamino)guanidines and mesoionic 1,2,4-triazolium-3-aminides

• Jan Szabo,
• Julian Greiner and
• Gerhard Maas

Beilstein J. Org. Chem. 2017, 13, 579–588, doi:10.3762/bjoc.13.57

• maximum in the series R = CH3 < phenyl ≈ 3,4,5-trimethoxyphenyl < 4-nitrophenyl. For 7a–c, this absorption band could result from a charge transfer between the amidinate moiety, representing the HOMO of the mesoionic system, and an unoccupied π-orbital of the C(=O)Ar group. Upon N-protonation or N

Synthesis and optical properties of new 5'-aryl-substituted 2,5-bis(3-decyl-2,2'-bithiophen-5-yl)-1,3,4-oxadiazoles

• Anastasia S. Kostyuchenko,
• Tatyana Yu. Zheleznova,
• Anton J. Stasyuk,
• Aleksandra Kurowska,
• Wojciech Domagala,
• Adam Pron and
• Alexander S. Fisyuk

Beilstein J. Org. Chem. 2017, 13, 313–322, doi:10.3762/bjoc.13.34

• the quantum-chemical predictions and the experiment. According to the theoretical results the observed transition is solely connected with the HOMO–LUMO transition. A careful analysis of frontier molecular orbitals disclosed a notable charge transfer from the central part to the terminal substituents

Spectral and DFT studies of anion bound organic receptors: Time dependent studies and logic gate applications

• Srikala Pangannaya,
• Neethu Padinchare Purayil,
• Shweta Dabhi,
• Venu Mankad,
• Prafulla K. Jha,
• Satyam Shinde and
• Darshak R. Trivedi

Beilstein J. Org. Chem. 2017, 13, 222–238, doi:10.3762/bjoc.13.25

• the transitions between the π orbital of the azomethine group and the OH functionality involved in an intramolecular charge-transfer process, respectively [38]. The incremental addition of 0.1 equiv of TBA salts of F− and AcO− resulted in a red shift of the original charge-transfer bands to 477 nm and

• exhibited a gradual decrease in intensity indicating the charge-transfer interactions occurring in the presence of the AcO− ion. The 1H NMR titration spectra of R1 and R2 in the presence of increasing concentrations of the AcO− ion are shown in Figure 15 and Figure 16. Theoretical studies In order to

• in the presence of F− and AcO− ions were also studied. A significant reduction of ΔE to 0.0679 Ha (R1 + F−), 0.04 (R1 + AcO−) and 0.08 Ha (R2 + F− and R2 + AcO−) confirms the presence of intramolecular charge-transfer transitions during the anion detection process. The similar values of ΔE observed

Characterization of the synthetic cannabinoid MDMB-CHMCZCA

• Carina Weber,
• Stefan Pusch,
• Dieter Schollmeyer,
• Sascha Münster-Müller,
• Michael Pütz and
• Till Opatz

Beilstein J. Org. Chem. 2016, 12, 2808–2815, doi:10.3762/bjoc.12.279

• inclusion of diffuse functions (def2-TZVPP vs ma-def2-TZVPP). The use of the range-separated (long-range corrected) CAM-B3LYP and ωB97XD functionals – probably more appropriate for the description of charge-transfer states – also did not lead to an improvement of the data. On the other hand, an assignment

Effects of solvent additive on “s-shaped” curves in solution-processed small molecule solar cells

• John A. Love,
• Shu-Hua Chou,
• Ye Huang,
• Guilllermo C. Bazan and
• Thuc-Quyen Nguyen

Beilstein J. Org. Chem. 2016, 12, 2543–2555, doi:10.3762/bjoc.12.249

• alternating electron-rich donor (D) and the electron-deficient acceptor (A) moieties so as to facilitate efficient photo-induced charge transfer and harvest a broad spectral response [9][10][11]. One such molecular architecture introduced by Bazan and co-workers can be described as a D1–A–D2–A–D1 system [12

A self-assembled cyclodextrin nanocarrier for photoreactive squaraine

• Ulrike Kauscher and
• Bart Jan Ravoo

Beilstein J. Org. Chem. 2016, 12, 2535–2542, doi:10.3762/bjoc.12.248

• singlet oxygen quenchers [23]. The authors discussed that this behaviour is based on charge-transfer processes between stacked squaraines as well as oxygen squaraine complexes. Within the same year, Rapozzi et al. described the photooxidation process of benzothiazol squaraines [24]. They showed that the

Thiophene-forming one-pot synthesis of three thienyl-bridged oligophenothiazines and their electronic properties

• Dominik Urselmann,
• Konstantin Deilhof,
• Bernhard Mayer and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2016, 12, 2055–2064, doi:10.3762/bjoc.12.194

• oligophenothiazines. TD-DFT and even semiempirical ZINDO calculations reproduce the trends of longest wavelengths absorption bands and allow the assignment of these transitions to possess largely charge-transfer character from the adjacent phenothiazinyl moieties to the central thienyl unit. Keywords: C–C coupling

• nature of these transitions possesses predominantly a charge-transfer character from the adjacent phenothiazinyl moieties to the central thiophene part. The intense coefficient density in the center of the structures in both HOMO (HOMO-2) and LUMO additionally supports and rationalizes the dominant

• semiempirical ZINDO calculations on geometry-optimized simplified structures of the title compounds nicely reproduce the trends of longest wavelength absorption bands and allow the assignment of these transitions to be largely charge-transfer from the adjacent phenothiazinyl moieties to the central thienyl unit

Synthesis and characterization of fluorinated azadipyrromethene complexes as acceptors for organic photovoltaics

• Forrest S. Etheridge,
• Roshan J. Fernando,
• Sandra Pejić,
• Matthias Zeller and
• Geneviève Sauvé

Beilstein J. Org. Chem. 2016, 12, 1925–1938, doi:10.3762/bjoc.12.182

• substitution at the pyrrolic phenylacetylene moieties. The later complexes are expected to be stronger electron acceptors than Zn(WS3)2, and may enable charge transfer from other conjugated polymer donors that have lower energy levels than poly(3-hexylthiophene) (P3HT). Keywords: dye; fluorine; near-IR

• addition of fluorine decreases the energy of the highest occupied molecular orbitals (HOMO), thereby enhancing the open-circuit voltages (Voc) and PCEs [17][23][24][25][26]. A 2014 investigation by Luscombe and co-workers showed that a fluorine substitution lowered the charge transfer exciton (CTE) binding

• expected to be stronger electron acceptors than Zn(WS3)2, and may enable charge transfer from other conjugated polymer donor that have lower energy levels than P3HT. Results and Discussion Synthesis The synthesis of ADP was carried out according to literature procedures [9][33]. The ADP-analogs with

Practical synthetic strategies towards lipophilic 6-iodotetrahydroquinolines and -dihydroquinolines

• David R. Chisholm,
• Garr-Layy Zhou,
• Ehmke Pohl,
• Roy Valentine and
• Andrew Whiting

Beilstein J. Org. Chem. 2016, 12, 1851–1862, doi:10.3762/bjoc.12.174

• suitability of general structure 1 as an electron donor for the design of charge transfer fluorophores. Finally, crystallographic analysis of the boronic esters 29 and 30 highlighted a subtle flattening of the DHQ structure when compared to the saturated THQ; a structural characteristic that was found to

Synthesis and properties of fluorescent 4′-azulenyl-functionalized 2,2′:6′,2″-terpyridines

• Adrian E. Ion,
• Liliana Cristian,
• Mariana Voicescu,
• Masroor Bangesh,
• Augustin M. Madalan,
• Daniela Bala,
• Constantin Mihailciuc and
• Simona Nica

Beilstein J. Org. Chem. 2016, 12, 1812–1825, doi:10.3762/bjoc.12.171

• results of TDDFT calculations showed that the longest wavelength absorption maximum originates from a π–π transition centered on the azulene moiety but having some azulene→central pyridine charge transfer as electrons from HOMO and LUMO+1 orbitals (Figure 6) are involved. The HOMO (orbitals 94 and 107 for

• the azulene moiety is twisted from the central pyridine ring to a greater extent in 4b. It becomes clear that the substitution on the azulene moiety tends to break the azulene/central pyridine planarity and possibly reduce the azulene→central pyridine charge transfer effect, hence affecting the

• (M062X) [40]. Of these four functionals, B3LYP and CAMB3LYP are hybrid functionals with 20% Hartree–Fock exchange content, the later one incorporated with enhanced Hartree–Fock (HF) exchange in the long-distance ranges in order to correctly describe the charge transfer (CT) states. TPSSH is a hybrid